Improvement in attachments to stem-winder-watch cases



J. PORTENBAOH. Attachment to Stem-Winder Watch-Gases.

Patented Jan. 7,1879.

jag-7 WITNESSES am 1w ATTORNEYS,

N. PETERS. FHDTO-LITHOGRAPHER. WASHINGTON, D c.

UNITED STATES PATENT OrFIon.

JOSEPH FOBTENBAOH, OF GARLSTADT, NEW? JERSEY.

IMPROVEMENT IN ATTACHMENTS T0 STEM-WlNDER-WATCH CASES.

Specification forming part of Letters Patent No. 2] 1,1 14, datedJanuary 7, 1879; application filed August 15, 1878.

To all 10710112 it may concern:

Be it known that I, Josnrn Fon'rnnnnon, of Oarlstadt, in the county ofBergen and State of New Jersey, have invented a new and ImprovedLock-Spring Attachment to Stein- TVinderTV-atch Cases, of which thefollowing is a specification:

In the accompanying drawing, Figure 1 represents a dianietricalcross-section of a watch-case center provided. with my improvement. Fig.2 is a similar section at right angles to that of Fig. 1, or takenthrough the line :0 :0. Fig. 3 is a detail, showing the old constructionof the lock-spring. Fig. 4 is a detail face view of the metallicpressure-plate.

Similar letters of reference indicate corresponding parts.

In ordinary stem-winders the stem of the pendant goes through a hole orslot (shown in Fig. 3) in the end of the lock-spring, which latter ispressed upon directly by the shoulder of the stem in order to open thewatch-case. The necessary sliding movement of the spring relative to thestern creates a tendency of the former to wear and bend the latter. Theobject of my invention is to overcome this difliculty.

The invention consists in a perforated nietallic plate iitted upon thewinding-stem and interposed between the lock-spring and the center ringof the watch-case, to operate the said spring at one side of and out ofcontact with the said stein.

A is the center ring of the watch-case, or, as it is generally called,the watch-case center. .8 is the pendant by which the watch-spring iswound, and by pressing upon which the case is opened. 0 is the ordinarylock-spring, with the exception that it has no hole for the stem to gothrough; but its end is cut away at 0 below the catch 0 sufficiently toleave a distance between the end of the spring 0 and the stem at of thependant, to allow of the said sliding motion of the end of the spring totake effect at one side of the stem without the former ever getting incontact with the latter. To convey the pressure upon the pendant B tothe spring 0 for opening the case, 1 interpose between the lock-spring Oand the center ring A a metallic plate, D, having a central perforation,(I, through which. the stem (1. is inserted, and which is large enoughfor the stem to turn in. In pressing the pendant the shoulder b of thestem a presses upon the annular surface of the plate 1) which surroundsthe hole (1, and the plate D in its turn acts upon the spring 0 torelease the catch 0, the sliding motion before referred to taking placebetween the spring 0 and the plate D, leaving the stem intact.

Having thus fully described my invention, I claim as new and desire tosecure by Letters Patent The perforated metallic plate D, fitted uponthe winding-stem a, and interposed between the lock-spring C and thewatch-case center A, to operate the spring 0 at one side of and out ofcontact with the stem a, substantially as shown and described.

OSEPH FORTENBACH.

Witnesses IJEOPOLD WINDIscn, MILTON Dnnnnnsr.

